3. (13 pts) A cylindrical bar of a carbon steel is subjected to reversed and rotating-bending fatigue tests. The S-N cur

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3 13 Pts A Cylindrical Bar Of A Carbon Steel Is Subjected To Reversed And Rotating Bending Fatigue Tests The S N Cur 1 (37.13 KiB) Viewed 25 times

3. (13 pts) A cylindrical bar of a carbon steel is subjected to reversed and rotating-bending fatigue tests. The S-N curve from fatigue test results is shown in the Figure below. (a) What is the fatigue limit for the carbon steel? (b) What is the fatigue strength at 1.0x10 cycles. (e) When a maximum stress of 385 MPa is applied for this test, estimate the fatigue life? (d) If the bar diameter is 20 mm, determine the maximum cyclic load F that may be applied to ensure that fatigue failure will never occur. Assume a factor of safety of 2.0 and that the distance between loadbearing points is 100 mm. Cycles to failure = 1E 3 Stress = 250 MPa 500 450 400 Stress amplitude (MPa) 350 300 250 10 10 107 10' 10° 10 10 Cycles to failure